The Armored Reconnaissance/Airborne Assault Vehicle (AR/AAV) M551 Sheridan combined a large gun/missile launcher with a light weight chassis. The Sheridan was developed for the US Army in the early 1960’s. Designed to meet the US Army’s requirement for a light weight tank that was air transportable and amphibious, the Sheridan used aluminum armor instead of steel. To further enhance its amphibious capability, the outer hull armor was surrounded by high density foam encased in thin aluminum. This helped to keep the weight of the Sheridan down to approximately 16.5 tons.
In terms of firepower, the Sheridan was armed with a 152mm gun-launcher M81 and one 50 and one 30 caliber machine gun. The 152mm gun-launcher was unique in that it fired both conventional rounds and guided missiles. The missile, designated MGM-51
Shillelagh, was loaded into the gun breech like a conventional round and when fired, was guided via signals transmitted from a box on the turret. It had a range of up to 3,000 meters.
The Sheridan first entered service during the Vietnam War in February 1969. After the Vietnam War, it remained in service with US Army cavalry regiments until withdrawn in 1978. However, a battalion remained in active service with the 82nd Airborne Division and saw combat during Operation Just Cause in 1989 and Operation Desert Shield/Storm in 1990/91. They were retired from service with the 82nd by 1996 but continued to see service as an opposing force “VISMOD” until 2003. As “VISMODs”, Sheridans sported dummy armor and gun tubes mounted to simulate Soviet vehicles. In this role, they were quite successful.
The Littlefield M551 is one of only a small handful of M551’s in private hands. It is was very thoroughly restored in the 1990’s and has been used extensively for events both on and off the MVTF’s location. It runs quite well and will sure to be a crowd favorite when displayed in the new museum.